You can change the class of an instance using drag-and-drop in the Instances Tab. To change the class of an instance:
Note: When you drag an instance to a new class, the fields in the
instance will change to match the slots in the class. If you drag an instance,
you may lose some of the information in your instance. This loss is permanent.
You cannot restore the information by dragging the instance back to the
original class. In addition, any changes you make will be evident wherever that
instance is referenced -- for example, if that instance appears as the value of a
field, the change will also occur in the field. Therefore, you should be sure
you want to make these changes before you drag an instance to a new class. You
can use the backreferences
button to see where this instance is referenced before changing its class. You
may also wish to save a backup of the project before you move instances. See Renaming
a Project for more information.